content: // Protocol Buffers - Google's data interchange format
  // Copyright 2008 Google Inc.  All rights reserved.
  // https://developers.google.com/protocol-buffers/
  //
  // Redistribution and use in source and binary forms, with or without
  // modification, are permitted provided that the following conditions are
  // met:
  //
  //     * Redistributions of source code must retain the above copyright
  // notice, this list of conditions and the following disclaimer.
  //     * Redistributions in binary form must reproduce the above
  // copyright notice, this list of conditions and the following disclaimer
  // in the documentation and/or other materials provided with the
  // distribution.
  //     * Neither the name of Google Inc. nor the names of its
  // contributors may be used to endorse or promote products derived from
  // this software without specific prior written permission.
  //
  // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  
  package com.google.protobuf;
  
  import static java.util.Arrays.asList;
  
  import java.util.Collections;
  import java.util.ConcurrentModificationException;
  import java.util.Iterator;
  import java.util.List;
  import junit.framework.TestCase;
  
  /**
   * Tests for {@link ProtobufArrayList}.
   */
  public class ProtobufArrayListTest extends TestCase {
    
    private static final ProtobufArrayList<Integer> UNARY_LIST = newImmutableProtoArrayList(1);
    private static final ProtobufArrayList<Integer> TERTIARY_LIST =
        newImmutableProtoArrayList(1, 2, 3);
    
    private ProtobufArrayList<Integer> list;
    
    @Override
    protected void setUp() throws Exception {
      list = new ProtobufArrayList<Integer>();
    }
    
    public void testEmptyListReturnsSameInstance() {
      assertSame(ProtobufArrayList.emptyList(), ProtobufArrayList.emptyList());
    }
    
    public void testEmptyListIsImmutable() {
      assertImmutable(ProtobufArrayList.<Integer>emptyList());
    }
    
    public void testModificationWithIteration() {
      list.addAll(asList(1, 2, 3, 4));
      Iterator<Integer> iterator = list.iterator();
      assertEquals(4, list.size());
      assertEquals(1, (int) list.get(0));
      assertEquals(1, (int) iterator.next());
      
      list.remove(0);
      try {
        iterator.next();
        fail();
      } catch (ConcurrentModificationException e) {
        // expected
      }
      
      iterator = list.iterator();
      list.set(0, 1);
      try {
        iterator.next();
        fail();
      } catch (ConcurrentModificationException e) {
        // expected
      }
      
      iterator = list.iterator();
      list.add(0, 0);
      try {
        iterator.next();
        fail();
      } catch (ConcurrentModificationException e) {
        // expected
      }
    }
    
    public void testMakeImmutable() {
      list.add(2);
      list.add(4);
      list.add(6);
      list.add(8);
      list.makeImmutable();
      assertImmutable(list);
    }
    
    public void testRemove() {
      list.add(2);
      list.add(4);
      list.add(6);
  
      list.remove(1);
      assertEquals(asList(2, 6), list);
  
      list.remove(1);
      assertEquals(asList(2), list);
  
      list.remove(0);
      assertEquals(asList(), list);
    }
    
    public void testGet() {
      list.add(2);
      list.add(6);
      
      assertEquals(2, (int) list.get(0));
      assertEquals(6, (int) list.get(1));
    }
    
    public void testSet() {
      list.add(2);
      list.add(6);
      
      list.set(0, 1);
      assertEquals(1, (int) list.get(0));
      list.set(1, 2);
      assertEquals(2, (int) list.get(1));
    }
  
    private void assertImmutable(List<Integer> list) {
      if (list.contains(1)) {
        throw new RuntimeException("Cannot test the immutability of lists that contain 1.");
      }
      
      try {
        list.add(1);
        fail();
      } catch (UnsupportedOperationException e) {
        // expected
      }
      
      try {
        list.add(0, 1);
        fail();
      } catch (UnsupportedOperationException e) {
        // expected
      }
      
      try {
        list.addAll(Collections.<Integer>emptyList());
        fail();
      } catch (UnsupportedOperationException e) {
        // expected
      }
      
      try {
        list.addAll(Collections.singletonList(1));
        fail();
      } catch (UnsupportedOperationException e) {
        // expected
      }
      
      try {
        list.addAll(new ProtobufArrayList<Integer>());
        fail();
      } catch (UnsupportedOperationException e) {
        // expected
      }
      
      try {
        list.addAll(UNARY_LIST);
        fail();
      } catch (UnsupportedOperationException e) {
        // expected
      }
      
      try {
        list.addAll(0, Collections.singleton(1));
        fail();
      } catch (UnsupportedOperationException e) {
        // expected
      }
      
      try {
        list.addAll(0, UNARY_LIST);
        fail();
      } catch (UnsupportedOperationException e) {
        // expected
      }
      
      try {
        list.addAll(0, Collections.<Integer>emptyList());
        fail();
      } catch (UnsupportedOperationException e) {
        // expected
      } 
  
      try {
        list.clear();
        fail();
      } catch (UnsupportedOperationException e) {
        // expected
      }
  
      try {
        list.remove(1);
        fail();
      } catch (UnsupportedOperationException e) {
        // expected
      }
      
      try {
        list.remove(new Object());
        fail();
      } catch (UnsupportedOperationException e) {
        // expected
      }
      
      try {
        list.removeAll(Collections.emptyList());
        fail();
      } catch (UnsupportedOperationException e) {
        // expected
      }
      
      try {
        list.removeAll(Collections.singleton(1));
        fail();
      } catch (UnsupportedOperationException e) {
        // expected
      }
      
      try {
        list.removeAll(UNARY_LIST);
        fail();
      } catch (UnsupportedOperationException e) {
        // expected
      }
      
      try {
        list.retainAll(Collections.emptyList());
        fail();
      } catch (UnsupportedOperationException e) {
        // expected
      }
      
      try {
        list.retainAll(Collections.singleton(1));
        fail();
      } catch (UnsupportedOperationException e) {
        // expected
      }
      
      try {
        list.retainAll(UNARY_LIST);
        fail();
      } catch (UnsupportedOperationException e) {
        // expected
      }
      
      try {
        list.set(0, 0);
        fail();
      } catch (UnsupportedOperationException e) {
        // expected
      }
    }
    
    private static ProtobufArrayList<Integer> newImmutableProtoArrayList(int... elements) {
      ProtobufArrayList<Integer> list = new ProtobufArrayList<Integer>();
      for (int element : elements) {
        list.add(element);
      }
      list.makeImmutable();
      return list;
    }
  }
  